1. Field of the Invention
The present invention relates to a switch; and more particularly to a switch designed for applications related to a low water cutoff.
2. Brief Description of Related Art
FIG. 1A shows an existing low water cutoff switch, e.g., having an integral brass base 7 made from solid brass. The existing low water cutoff switch is a general purpose liquid flow switch sold under the model no. FS250, e.g., by the assignee of the instant patent application. See an Instruction Manual (MM-625C), entitled “Series FS-250 General Purpose Liquid Flow Switch,” which is hereby incorporated by reference.
In FIG. 1A, the existing low water cutoff switch includes the following labeled parts/components:
a plastic cover 1;
a micro switch 2;
a switch bracket 3;
a NPT plug;
a grub screw 5;
a pivot 6;
the brass base 7;
a paddle arm 8;
a paddle 9,
an actuating cam 10; and
an O-ring 11.
The existing low water cutoff switch is characterized as follows:
Basic Function:                To transfer oscillatory motion (because of liquid flow in the pipe where the switch is mounted) into vertical motion, which would actuate the micro switch 2 through the actuating cam 10 and ON/OFF signaling would be further passed on from the low cutoff switch to a given system for taking any further necessary action.        
Existing Problem:
Yielding of pivot mechanism can lead to failure, and                Development of condensation, e.g., when flow switches are used in chiller applications.        
FIG. 1B shows part of the existing low water cutoff switch in FIG. 1A, e.g., showing how the O rings 11 may be configured in part of the existing low water cutoff switch in relation to the pivot 6. FIG. 1C shows the integral brass base that forms part of the existing low water cutoff switch in FIG. 1A.
In effect, and by way of example, in the existing design the major base component is made of solid brass. When such a configuration is used in chiller application, it can result in condensation build-up in the existing low water cutoff switch, because of a heat transfer through conduction and convection, which over period of time has a tendency to make the flow switch un-operational.
There is a need to provide a better low cut-off switch that does not have such problems.